Wireless passive flexible accelerometer fabricated using micro-electro-mechanical system technology for bending structure surfaces

Abstract

We propose an inductor-capacitor (LC) wireless passive flexible accelerometer, which eliminates the difficulty in measuring the acceleration on the surface of a bending structure. The accelerometer is composed of a flexible polyimide (PI) substrate and a planar spiral inductance coil (thickness 300 nm), made using micro-electro-mechanical system (MEMS) technology. It can be bent or folded at will, and can be attached firmly to the surface of objects with a bending structure. The principle of radio frequency wireless transmission is used to measure the acceleration signal by changing the distance between the accelerometer and the antenna. Compared with other accelerometers with a lead wire, the accelerometer can prevent the lead from falling off in the course of vibration, thereby prolonging its service life. Through establishment of an experimental platform, when the distance between the antenna and accelerometer was 5 mm, the characterization of the surface of bending structures demonstrated the sensing capabilities of the accelerometer at accelerations of 20–100 m/s². The results indicate that the acceleration and peak-to-peak output voltage were nearly linear, with accelerometer sensitivity reaching 0.27 mV/(m·s⁻²). Moreover, the maximum error of the accelerometer was less than 0.037%.

摘要

提出一种LC无线无源柔性加速度计, 解决测量弯曲结构表面加速度的困难。 该加速度计由柔性聚酰亚胺 (PI) 衬底和平面螺旋电感 (厚度为300 nm) 组成, 采用微机电系统 (MEMS) 技术, 可任意弯曲或折叠, 可牢固地粘附在具有弯曲结构的物体表面。利用射频无线传输原理, 通过改变加速度计与天线之间的距离来测量加速度信号。与带导线的加速度计相比, 该加速度计可以防止导线在振动过程中脱落, 从而延长其使用寿命。通过搭建实验平台, 当天线与加速度计之间的距离为5 mm时, 在弯曲结构表面展示了加速度计在20至100 m/s2加速度下的传感能力。结果表明, 加速度和峰峰值输出电压接近线性, 加速度计灵敏度高达0.27 mV/(m·s⁻²)。此外, 该加速度计的最大误差小于0.037%。